Markers of Insulin Resistance Are Strong Risk Factors for Retinopathy Incidence in Type 1 Diabetes
The EURODIAB Prospective Complications Study
- Nish Chaturvedi, MRCP,
- Anne-Katrin Sjoelie, MD,
- Massimo Porta, MD,
- Steven J. Aldington, FBIPP,
- John H. Fuller, FRCP,
- Marco Songini, MD,
- Eva M. Kohner, FRCOPHTH and
- The EURODIAB Prospective Complications Study Group
- From the EURODIAB Prospective Complications Study (N.C., J.H.F.), University College London; the Department of Medicine (E.M.K.), St Thomas' Hospital Medical School; the Retinopathy Grading Center (S.J.A.), Imperial College School of Medicine, Hammersmith Campus, London, U.K.; the Department of Ophthalmology (A.-K.S.), Odense University Hospital, Odense, Denmark; Instituto di Medicina Interna (M.P.), Universita di Torino, Turin; and the Department of Internal Medicine (M.S.), Ospedale San Michele, Cagliari, Italy.
- Address correspondence and reprint requests to Nish Chaturvedi, MRCP, Department of Epidemiology and Public Health, Imperial College of Medicine at St. Mary's, Norfolk Place, London W2 1PG, U.K. E-mail: n.chaturvedi{at}ic.ac.uk .
Abstract
OBJECTIVE— To determine the incidence of retinopathy and the relative importance of its risk factors in type 1 diabetes.
RESEARCH DESIGN AND METHODS— This is a 7.3-year follow-up of 764 of 1,215 (63%) people with type 1 diabetes across Europe, aged 15-60 years at baseline with no retinopathy (the EURODIAB Prospective Complications Study). Retinal photographs were taken at baseline and follow-up and risk factors were assessed to a standard protocol.
RESULTS— Retinopathy incidence was 56% (429/764, 95% CI 52-59%). Key risk factors included diabetes duration and glycemic control. We found no evidence of a threshold effect for HbAlc on retinopathy incidence. Univariate associations were observed between incidence and albumin excretion rate, cholesterol, triglyceride, fibrinogen, von Willebrand factor, γ-glu-tamyltransferase, waist-to-hip ratio, and insulin dose. No associations were observed for blood pressure, cardiovascular disease, or smoking. Independent risk factors, as assessed by standardized regression effects, were HbAlc (1.93, P = 0.0001), duration (1.32, P = 0.008), waist-to-hip ratio (1.32, P = 0.01), and fasting triglyceride (1.24, P = 0.04).
CONCLUSIONS— Retinopathy incidence in type 1 diabetes remains high. Key risk factors include diabetes duration and glycemic control, with no evidence of a threshold for the latter. Other independent risk factors, such as waist-to-hip ratio and triglyceride levels, both markers of insulin resistance, were strongly related to incidence.
Footnotes
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Abbreviations: DCCT, Diabetes Control and Complications Trial; PCS, Prospective Complications Study; SRE, standardized regression estimate; vWF, von Willebrand factor.
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A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
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- Accepted November 1, 2000.
- Received July 25, 2000.
- by the American Diabetes Association, Inc.
